Microphone, often used in online games such as Counter-Strike. There are usually three types of people who use it:

1) The 20-year-old guy who makes good use of it by communicating with his team
2) The moron who likes to scream at people on his team, usually resulting in garbled screeching
3) The 10-year-old who barks orders at his teammates when he's losing and shouts "Yipee" when he's winning, only to sound ridiculous either way

I was on a server last night where everyone used a mic. I went to sleep with bleeding ears.

Offensive term for a person of Irish or Scottish descent. Intended to mock the common Mc- or Mac- prefix on their names. Used by anyone without a Scottish/Irish accent or at least red hair will result in an ass beating.

Put down that whisky you filthy drunken Mic!

Ach, yew kin take oor freedom, but yew kin never take oor Scotch! Ne'er troi to take th' alkohool o' a Mic!

(tech jargon) An acronym standing for "Made In China" use to describe poor manufactured textiles, automobiles, parts or anything that is considered to be defective. Colloquial use by those in the Southeastern United States following the recall of several Made in China products, tooth paste, toys, etc. Often use to describe a person that is considered as "defective" with one or more personality flaws, e.g., someone that is unable to get along with others. It should be noted that the acronym is pronouced like the word "mike" and not like the derogatory term used to describe someone of Irish ethnicity.

Damn, John, your car won't start again. I told you not to buy the M.I.C. car.
John's M.I.C. personality really wins him the Asshole of the Year Award.
Man, this hamburger really blows. I bet it's a M.I.C.